TIPPING

In most stamping simulations, the global Z direction is selected as the stamping direction. Some part designs might not be compatible with the default setting of eta/DYNAFORM. Therefore the tipping function is used to adjust the product to follow the stamping direction. It allows the user to translate and/or rotate the part about a defined axis. The TIPPING dialog box is illustrated in Figure 6.1.46.

Figure 6.1.46  Tipping interface

 

Before tipping, there are some parts already existing in the part list, as shown in Figure 6.1.46. When defining some parts as DIE in the previous DEFINE interface, the program automatically adds these parts into the Include Part List on the Tipping interface.

 

For the adjustment of stamping direction of double attach, the stamping direction is divided into GENERAL TIPPING and DOUBLE ATTACH TIPPING.

 

6.1.3.1  GENERAL TIPPING

This function enables the user to tip all parts except double attach. During DIE tipping, all geometry in DIE including surfaces, lines and points will be rotated and translated with the die mesh, as illustrated in Figure 6.1.47.

Tipping8

Figure 6.1.47  General tipping

 

6.1.3.2  DOUBLE ATTACH TIPPING

This function enables the user to tip double attach. There are two types of double attach: symmetry and asymmetry, so the double attach tipping also has two types: LEFT/RIGHT HALF/FULL INPUT and TWO PARTS.

 

l   LEFT/RIGHT HALF/FULL INPUT

This function contains three types of TIPPING, as illustrated in Figure 6.1.48.

Tipping9

Figure 6.1.48  Left/right half/full input

Tipping10 TIP LEFT SIMU RIGHT

This type of TIPPING uses the tipping center of the left part as base point to tip the left part and tip the right part simultaneously through symmetry plane mirroring.

 

Tipping11 TIP RIGHT SIMU LEFT

This type of TIPPING uses the tipping center of the right part as base point to tip the right part and tip the left part simultaneously through symmetry plane mirroring.

 

Tipping12 TIP ALL

This type of TIPPING uses the middle point of the connection line between two tipping centers of the left part and right part as base point to rotate (translate) the left and right parts about (along) a direction.

 

l   TWO PARTS

This function contains two types of TIPPING, as illustrated in Figure 6.1.49.

Tipping13

Figure 6.1.49  Two parts

Tipping14 TIP LEFT

This type of TIPPING uses the tipping center of the left part as base point to tip the left part without tipping of the right part.

 

Tipping15 TIP RIGHT

This type of TIPPING uses the tipping center of the right part as base point to tip the right part without tipping of the left part.

 

6.1.3.3  PART LIST

This function enables the user to add the parts that need tipping into the list using ADD button, or delete the unnecessary parts from the list using REMOVE button, as illustrated in Figure 6.1.50.

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Figure 6.1.50  Part list

NOTE: After tipping, the ADD and REMOVE buttons are disabled so that the user cannot add or delete parts. After defining double attach, these two buttons will also be disabled.

 

6.1.3.4  TIPPING CENTER

This function enables the user to define a point as the origin of the tipping coordinate system. All the tipping operations will be performed in this coordinate system, as illustrated in Figure 6.1.51. The default tipping center is the center of mass of the selected part.

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Figure 6.1.51  Tipping center

USER DEFINE button enables the user to define a new tipping center according to requirements. Click this button to display a dialog box illustrated in Figure 6.1.52. Refer to Section 5.1.1 for detailed description about defining point/node. The user may click nodes using mouse cursor or input value to select tipping center and click OK to confirm.

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Figure 6.1.52  Select tipping center

l   GENERAL TIPPING

For general parts, there is only one tipping center to be used as the origin of tipping coordinate for tipping.

 

l   LEFT/RIGHT HALF/FULL INPUT

For symmetric double attach, the left part and right part have their own tipping centers which are symmetric about the symmetry plane. After the tipping center of the left part (or right part) is defined, the program will automatically obtain the tipping center of the right part (or left part) according to the symmetry plane.

 

l   TWO PARTS

For asymmetric double attach, the left part and right part have their own tipping centers which have no connection. The tipping centers for the left part and right part need to be defined respectively.

 

6.1.3.5  AUTO TIPPING

eta/DYNAFORM provides four methods for auto tipping and user define, as illustrated in Figure 6.1.53.

Auto Tipping

Figure 6.1.53  Auto Tipping

 

l   AVERAGE NORMAL

This function automatically rotates the part to an appropriate stamping position by averaging all normal vectors of elements to minimize undercut, as illustrated in Figure 6.1.54.

  

Before Tipping                              After Tipping

Figure 6.1.54  Tipping Check

 

l   SURFACE NORMAL

This function enables the user to tip by using the normal of the selected surface.

 

l   MIN DRAW DEPTH

This function enables the user to tip by calculating the minimum draw depth of part.

 

l   MAX WIDTH

Calculate the maximum width of part and keep it consistent with U direction. The part only rotates about W axis during tipping.

 

USER DEFINE

This function allows the user to define stamping direction by defining direction vector. Clicking this button, the program will pop up a Vector dialog box illustrated in Figure 6.1.55. Refer to Section 5.1.4  Shortest Curve for detailed description about defining direction vector.

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Figure 6.1.55  Define vector

 

6.1.3.6  MANUAL TIPPING

In manual tipping operation, the part can be rotated/translated about/along the U-, V-, or W-axis, as shown in Figure 6.1.56. Using the rotation/translation about/along the U-, V-, or W-axis to perform the tipping operation according to the Increment defined in the dialog box. The tipping check will be visible if the checkbox for UNDERCUT or DRAW DEPTH button is toggled on.

Tipping2

Figure 6.1.56  Manual Tipping

 

l   ROTATION

Select ROTATION AXIS and key in any absolute rotation angle in the input field.  Click on Tipping6 or Tipping5 button that represents the rotation axis to rotate the model with defined angle about the selected axis.

 

l   TRANSLATION

If TRANSLATION AXIS option is selected, the Tipping4 or Tipping3 button represents translation direction.  The value in the input field of TRANSLATION is the incremental displacement along the selected axis.

 

6.1.3.7  PROCESS RECORD

This function automatically records all the operations (rotation and translation) during tipping and enables the user to EXPORT and IMPORT operation steps, as illustrated in Figure 6.1.57.

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Figure 6.1.57  Record operation steps

24 IMPORT

Click IMPORT button to import the file with the recorded operation steps. The parts in the part list will perform tipping automatically according to the operation steps in the file.

 

NOTE: If the current part has operation steps, the program will prompt the user to delete the existing steps before importing the file.

MUST CLEAR ALL STEPS IN PROCESS RECORD

If the tipping center of the imported file is different from the currently defined tipping center, the program will prompt the user if the file tipping center should be used as base point to tip part, as illustrated in Figure 6.1.58.

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Figure 6.1.58  DYNAFORM question dialog box

Click YES to use the file tipping center as base point. Perform tipping on the part automatically according to the operation steps in the file and use the file tipping center to replace the defined tipping center in TIPPING page.

 

Click NO to use the defined tipping center as base point. Perform tipping on the part automatically according to the operation steps in the file.

 

25 EXPORT

Click EXPORT button to export all the recorded operation steps to a file.

 

26 COMBINE

If the adjacent operation steps share the same coordinate axis for rotation and translation, click this button to combine these steps into one step.

 

27 RE-CALCULATE

When changing the values for the last step in the operation steps record list, click this button to recalculate tipping.

 

50 DELETE

Allow the user to delete the last step.

 

6.1.3.8  TIPPING RESULT

This function is used to record the Traanslate and Rotate result of parts.

 

l   General Tipping Result

 

The general tipping result is illustrated in Figure 6.1.59.

 

Tra. (Translate) shows the translation results along X, Y and Z directions by sequence.

 

Rot. (Rotate) shows the rotation result about X, Y and Z axis by sequence.

 

Figure 6.1.59  General tipping result

l   Double Attached Tipping Result

 

The double attached tipping result is illustrated in Figure 6.1.60. It shows the translation and rotation results of left part (L.) and right part (R.) respectively.

 

Figure 6.1.60  Double attached tipping result

6.1.3.9  TIPPING CHECK

This function allows the user to check the result after tipping operation, as shown in Figure 6.1.61.

Figure 6.1.61  Check tipping

 

l  PART DEPTH

This function displays a contour plot showing the parth depth of part relative to the binder.  Different path depths are displayed in graduated colors on the die.  Part depth is estimated with reference positon at the first point of punch/die contact with the blank.  When the die/punch is closed, the first point on the blank to contact with the punch is locked.  The rest of the part will be stretched from this point spreading outward.

 

l  UNDERCUT

This function displays a contour plot showing regions in the die with undercut. Red indicates severe undercut where the backdraft is less than 0º. Yellow indicates a marginal area with a draw angle of approximately 0~3º.  Green indicates a safe region with a draw angle that is greater than 3º. The user can set the threshold for marginal and severe backdraft. Click 29 button to display a dialog box as illustrated in Figure 6.1.62.

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Figure 6.1.62  Undercut Limit dialog box

 

l  WALL ANGLE

Once this option is selected, the program displays a contour plot showing wall angle on the die. Different wall angles are displayed in different colors. The user can point the cursor to any node on the selected part and click on the left mouse button to show the wall angle at this node, as illustrated in Figure 6.1.63.

Figure 6.1.63  Display Wall Angle

 

6.1.3.10  RESET TIPPING OPERATION

 

The RESET function will cancel all tipping operations and restore the part to the initial position.

 

NOTE: For LEFT/RIGHT HALF/FULL INPUT, click RESET button to restore the left and right parts to the initial positions. 

 

For TWO PARTS, if TIP LEFT is selected, click RESET button to restore the left part to the initial position without any change of the right part position. If TIP RIGHT is selected, click RESET button to restore the right part to the initial position without any change of the left part position.